The present invention relates to a backlight module of a liquid crystal display (LCD) and, more particularly, to a filed emitting/emission display (FED) device, such as one having a plurality of carbon nanotubes, incorporated into a backlight module of an LCD.
Displays are the most direct sensory interfaces between humans and televisions and between humans and electronic/information products. The quality of a display directly influences the visual feel of the user or even the emotion of the user. Therefore, there are more and more efforts devoted to researches relevant to displays. The research points of emphasis focus on how to switch from monochromatic, low-resolution, bulky, highly power-dissipating, small area displays to color, high-resolution, compact, lowly power-dissipating, large area displays. Because LCDs have the characteristics of thin shape, light weight, low power dissipation, they have been widely used as large displays such as screens of desktop computers and small displays such as portable information terminals. The rate of usage of LCDs gradually increases.
In an LCD, the characteristics of electrical induction and optical anisotropy of liquid crystal material are exploited. The liquid crystal material has good molecular orientation and fluidity characteristics. When the liquid crystal material is subject to external excitations such as illumination, heat, electrical field, and magnetic field, its molecular orientation will easily be altered so that brightness contrast will change or other special electrical and optical effects will emerge when light penetrates through it. However, an LCD is not a self-luminescent display. Therefore, a backlight module is required to achieve the object of displaying. For the present middle-size LCDs, cold cathode fluorescent lamps (CCFLs) are used as the light sources. Although CCFLs have good displaying effect in terms of uniformity and brightness, power supplies of high voltage (xcx9c800 V) are required. This is a detrimental drawback to portable displays. Additionally, the characteristics of a CCFL will be affected by temperature to greatly decrease its lifespan so that an LCD cannot be used in rigorous regions such as deserts, snowing regions, and so on. Moreover, using a CCFL as a backlight module of an LCD will result in a higher cost.
A field emitting display (FED) is a kind of high-quality flat display. It is the only one super-thin flat display comparable to the CRT in terms of quality of image. An FED has the advantages of high brightness and high resolution. However, it still requires a higher driving voltage. In order to let field emitting arrays be practical, the development of field emitting cathodes must tend toward low operational voltage and high efficiency. Recently, a kind of compound made mainly of carbon has been developed. This kind of compound made mainly of carbon is carbon nanotube. The carbon nanotubes can greatly reduce the required operational voltage of an FED, and has good characteristics of field-emitted current and good mechanical properties. The carbon nanotubes thus have the potential of becoming high-performance field emitting electrodes.
The present invention aims to propose the design of using an FED as a backlight source of an LCD to effectively solve the above problems in the prior art.
The primary object of the present invention is to provide an FED made of carbon nanotubes as a backlight module of an LCD for providing the required light source for the display. The present invention has a rather low operational voltage to overcome the drawback of requiring a high operational voltage for a prior art CCFL LCD.
Another object of the present invention is to provide an FED having the characteristics of high brightness, power saving, and super thinness so that it can be used in rigorous environments and will not be limited by temperature.
To achieve the above objects, in the present invention, an FED having carbon nanotubes is disposed at a backlight position of a liquid crystal panel module of an LCD to be used as a backlight module and to replace the prior art CCFL.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which: